Elastomeric compositions

ABSTRACT

The present invention includes compositions suitable for air barriers such as innerliners where adhesion to tire carcass materials (e.g., SBR) and flexibility are desirable, as well as low air permeability. The invention includes a tire innerliner made by combining a filler; a sulfur cure system; optionally at least one secondary rubber; and at least one halogenated terpolymer of C 4  to C 8  isoolefin derived units, C 4  to C 14  multiolefin derived units, and p-alkylstyrene derived units. Examples of suitable fillers include modified carbon black, carbon black, silica, exfoliated clays, and combinations thereof. The present invention also includes a method of producing an elastomeric terpolymer composition comprising combining in a diluent C 4  to C 8  isoolefin monomers, C 4  to C 14  multiolefin monomers, and p-alkylstyrene monomers in the presence of a Lewis acid and at least one initiator to produce the terpolymer. Examples of suitable initiators include cumyl compounds and or halogenated organic compounds, especially secondary or tertiary halogenated compounds such as, for example, t-butylchloride, 2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane (cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethyl ether)); the cumyl halides, particularly the chlorides, such as, for example 2-chloro-2-phenylpropane, cumyl chloride (1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene (di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene (tri(cumylchloride)); the aliphatic halides, particularly the chlorides, such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl), and 2-bromo-2,4,4-trimethylpentane (TMPBr).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Application of InternationalApplication No. PCT/US02/39363, filed Dec. 9, 2002, which claims thebenefit of Provisional Application Nos. 60/339,966, filed Dec. 10, 2001and 60/381,326, filed May 17, 2002.

FIELD OF INVENTION.

The present invention relates to compositions of isobutylene-basedterpolymers. More particularly, the invention relates to terpolymercompositions, wherein the terpolymer includes isoolefin derived units,styrenic derived units, and multiolefin derived units, the compositionsbeing useful in tires, particularly in automotive components such astreads, belts, tire innerliners, innertubes, and other air barriers.

BACKGROUND OF THE INVENTION

Isobutylene-based terpolymers including isoolefin, styrenic, andmultiolefin derived units have been disclosed in U.S. Pat. Nos.3,948,868, 4,779,657; and WO 01/21672. Compositions useful for airbarriers such as innerliners and innertubes which include suchterpolymers are not known.

Improving the specific properties of tire innerliners withoutsacrificing current performance is desirable. Use of isobutylene-basedelastomers such as butyl rubber (IIR), halobutyl rubbers (chloro (CIIR)or bromo (BIIR)) or brominated isobutylene-co-p-methylstyrene (BIMS) asthe innerliner polymer serves to provide for decreased permeability toair compared to general purpose elastomers (such as NR, BR, or SBR) ortheir blends with isobutylene elastomers. Flex fatigue resistance,adhesion to other tire components such as carcass and bead compounds,and abrasion resistance are also desirable performance properties. Useof BIMS copolymers increases the compatibility of the innerliner withGPR hydrocarbon elastomers; however, co-vulcanization using sulfur curesystems is still not achieved to a sufficiently high degree. Improvedlab adhesion values to carcass compounds is still desirable.

To be useful in, for example, a tire tread or tire sidewall as part of amulti-component automobile tire, the terpolymer must desirably be bothsulfur curable, and compatible with other rubbers such as natural rubberand polybutadiene. Further, in order to serve as an air barrier such asa tire innerliner, the terpolymer compositions must be air impermeable,adhere well to the tire carcass such as a poly(styrene-co-butadiene)(SBR) carcass, and have suitable durability. These properties are oftendifficult to achieve together, as improving one can often diminish theother.

It is unexpected that the incorporation of a multiolefin derived unit ina composition including a polymer having a isobutylene/p-methylstyrenebackbone would contribute to both improved carcass adhesion andflexibility, while maintaining air impermeability. Likewise, it isunexpected that such terpolymer will sulfur cure in light of the IB/PMScopolymers failing to sulfur vulcanize. Yet, the inventors heredemonstrate, among other things, the practical use of certainisoolefinic terpolymers that incorporate multiolefins that are sulfurcurable. More particularly, it has been discovered that theseterpolymers are useful in curable blends with suitable fillers and thelike due to improved traction and abrasion performance, thus makingthese compositions useful in tire treads, sidewalls as well as airbarriers such as innerliners and innertubes for pneumatic tires.

Other background references include U.S. Pat. Nos. 3,560,458 and5,556,907 and EP 1215 241 A.

SUMMARY OF THE INVENTION

These and other problems are solved by a terpolymer prepared byincorporating isobutylene (IB) along with isoprene (I) andpara-methylstyrene (MS) derived units. The isoprene is desirably presentin sufficient concentration in the terpolymer to promote vulcanizationby conventional sulfur curing ingredients. In addition, the terpolymercan be halogenated to further enhance crosslinking reactions. Thus,halogen atoms, desirably chlorine or bromine, can be incorporated ontothe isoprene moiety in the backbone of the terpolymer such as inbromobutyl rubber, or onto the backbone and the methyl group of themethylstyrene. These reactive sites can allow for crosslinking of thehalogenated terpolymer with itself, and also with hydrocarbon dienerubbers used in tire carcass compounds, such as NR, BR and SBR.

The present invention includes compositions suitable for air barrierssuch as innerliners or innertubes for automobile tires and otherarticles where air impermeability and flexibility are desirable. Theinvention includes an automotive innerliner made from a composition ofat least one (i.e., one or more) filler; a sulfur cure system; andoptionally at least one secondary rubber; and at least one halogenatedterpolymer of C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefinderived units, and p-alkylstyrene derived units. In one embodiment, theterpolymer is halogenated. Examples of suitable fillers include but arenot limited to carbon black, modified carbon black, silica, so callednanoclays or exfoliated clays, and combinations thereof.

The present invention also includes a method of producing an elastomericterpolymer composition comprising combining in a diluent having adielectric constant of at least 6 in one embodiment, and at least 9 inanother embodiment: C₄ to C₈ isoolefin monomers, C₄ to C₁₄ multiolefinmonomers, and p-alkylstyrene monomers in the presence of a Lewis acidand at least one initiator to produce the terpolymer. Examples ofsuitable initiators include t-butylchloride, 2-acetyl-2-phenylpropane(cumyl acetate), 2-methoxy-2-phenyl propane (cumylmethyl-ether),1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethyl ether)); the cumylhalides, particularly the chlorides, such as, for example2-chloro-2-phenylpropane, cumyl chloride(1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (TMPCl),2-bromo-2,4,4-trimethylpentane (TMPBr), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobomane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzene andsimilar compounds or mixtures of such compounds as listed above.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a plot of tangent delta (G″/G′) values as a function oftemperature for example 4 (SBB), 5 (BIIR), 6 (BIMS) and 7 (BrIBIMS), allincluding in the composition carbon black.

DETAILED DESCRIPTION OF THE INVENTION

The present invention includes a method of making isobutylene-basedterpolymers including isobutylene derived units, styrenic derived units,and multiolefin derived units, and compositions of these terpolymers andhalogenated terpolymers. The terpolymers of the present invention can bemade via carbocationic polymerization processes using a mixture of atleast the monomers, a Lewis acid catalyst, an initiator, and a diluent.The polymerization is typically carried out either in slurry such as ina continuous slurry reactor or butyl-type reactor, or in solution. Thecopolymerization reactor is maintained substantially free of impuritieswhich can complex with the catalyst, the initiator, or the monomers. Bysubstantially free of impurities, it is meant that the impurities are ata level of no greater than 100 ppm. Anhydrous conditions are preferredand reactive impurities, such as components containing active hydrogenatoms (water, alcohol and the like) are desirably removed from both themonomer and diluents by techniques well-known in the art. Theseimpurities, such as water, are present, if at all, to an extent nogreater than 500 ppm in one embodiment.

As used herein, the term “catalyst system” refers to and includes anyLewis Acid or other metal complex used to activate the polymerization ofolefinic monomers, as well as the initiator described below, and otherminor catalyst components described herein.

As used herein, the term “polymerization system” includes at least thecatalyst system, diluent, the monomers and reacted monomers (polymer)within the butyl-type reactor. A “butyl-type” reactor refers to anysuitable reactor such as a small, laboratory scale, batch reactor or alarge plant scale reactor. One embodiment of such a reactor is acontinuous flow stirred tank reactor (“CFSTR”) is found in U.S. Pat. No.5,417,930. In these reactors, slurry (reacted monomers) is circulatedthrough tubes of a heat exchanger by a pump, while boiling ethylene onthe shell side provides cooling, the slurry temperature being determinedby the boiling ethylene temperature, the required heat flux and theoverall resistance to heat transfer.

As used herein, the term “diluent” means one or a mixture of two or moresubstances that are liquid or gas at room temperature and atmosphericpressure that can act as a reaction medium for polymerization reactions.

As used herein, the term “slurry” refers to reacted monomers that havepolymerized to a stage that they have precipitated from the diluent. Theslurry “concentration” is the weight percent of these reactedmonomers—the weight percent of the reacted monomers by total weight ofthe slurry, diluent, unreacted monomers, and catalyst system.

The term “elastomer” may be used interchangeably with the terms“rubber”, as used herein, and is consistent with the definition in ASTM1566.

As used herein, the new numbering scheme for the Periodic Table Groupsare used as in HAWLEY'S CONDENSED CHEMICAL DICTIONARY 852 (13th ed.1997).

As described herein, polymers and copolymers of monomers are referred toas polymers or copolymers including or comprising the correspondingmonomer “derived units”. Thus, for example, a copolymer formed by thepolymerization of isoprene and isobutylene monomers may be referred toas a copolymer of isoprene derived units and isobutylene derived units.

As used herein the term “butyl rubber” is defined to mean a polymerpredominately comprised of repeat units derived from isoolefins such asisobutylene but including repeat units derived from a multiolefin suchas isoprene; and the term “terpolymer” is used to describe a polymerincluding isoolefin derived units, multiolefin derived units, andstyrenic derived units.

As used herein, the term “styrenic” refers to any styrene or substitutedstyrene monomer unit. By substituted, it is meant substitution of atleast one hydrogen group by at least one substituent selected from, forexample, halogen (chlorine, bromine, fluorine, or iodine), amino, nitro,sulfoxy (sulfonate or alkyl sulfonate), thiol, alkylthiol, and hydroxy;alkyl, straight or branched chain having 1 to 20 carbon atoms; alkoxy,straight or branched chain alkoxy having 1 to 20 carbon atoms, andincludes, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy,isobutoxy, secondary butoxy, tertiary butoxy, pentyloxy, isopentyloxy,hexyloxy, heptryloxy, octyloxy, nonyloxy, and decyloxy; haloalkyl, whichmeans straight or branched chain alkyl having 1 to 20 carbon atoms whichis substituted by at least one halogen, and includes, for example,chloromethyl, bromomethyl, fluoromethyl, iodomethyl, 2-chloroethyl,2-bromoethyl, 2-fluoroethyl, 3-chloropropyl, 3-bromopropyl,3-fluoropropyl, 4-chlorobutyl, 4-fluorobutyl, dichloromethyl,dibromomethyl, difluoromethyl, diiodomethyl, 2,2-dichloroethyl,2,2-dibromomethyl, 2,2-difluoroethyl, 3,3-dichloropropyl,3,3-difluoropropyl, 4,4-dichlorobutyl, 4,4-difluorobutyl,trichloromethyl, 4,4-difluorobutyl, trichloromethyl, trifluoromethyl,2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl, 1,1,2,2-tetrafluoroethyl,and 2,2,3,3-tetrafluoropropyl.

As used herein, the term “substituted aryl” means phenyl, naphthyl andother aromatic groups, substituted by at least one substituent selectedfrom, for example, halogen (chlorine, bromine, fluorine, or iodine),amino, nitro, sulfoxy (sulfonate or alkyl sulfonate), thiol, alkylthiol,and hydroxy; alkyl, straight or branched chain having 1 to 20 carbonatoms; alkoxy, straight or branched chain alkoxy having 1 to 20 carbonatoms, and includes, for example, methoxy, ethoxy, propoxy, isopropoxy,butoxy, isobutoxy, secondary butoxy, tertiary butoxy, pentyloxy,isopentyloxy, hexyloxy, heptryloxy, octyloxy, nonyloxy, and decyloxy;haloalkyl, which means straight or branched chain alkyl having 1 to 20carbon atoms which is substituted by at least one halogen, and includes,for example, chloromethyl, bromomethyl, fluoromethyl, iodomethyl,2-chloroethyl, 2-bromoethyl, 2-fluoroethyl, 3-chloropropyl,3-bromopropyl, 3-fluoropropyl, 4-chlorobutyl, 4-fluorobutyl,dichloromethyl, dibromomethyl, difluoromethyl, diiodomethyl,2,2-dichloroethyl, 2,2-dibromomethyl, 2,2-difluoroethyl,3,3-dichloropropyl, 3,3-difluoropropyl, 4,4-dichlorobutyl,4,4-difluorobutyl, trichloromethyl, 4,4-difluorobutyl, trichloromethyl,trifluoromethyl, 2,2,2-trifluoroethyl, 2,3,3-trifluoropropyl,1,1,2,2-tetrafluoroethyl, and 2,2,3,3-tetrafluoropropyl. An “aryl” groupis any aromatic ring structure such as a phenyl or naphthyl group.

Butyl-type rubber is an isobutylene-based polymer produced by thepolymerization reaction between isoolefin and a conjugated diene—ormultiolefinic—comonomers, thus containing isoolefin-derived units andmultiolefin-derived units. The terpolymers of the present invention areprepared in a manner similar to that for traditional butyl rubbersexcept that an additional comonomer (e.g., a styrenic monomer) is alsoincorporated into the polymer chains. The olefin polymerization feedsemployed in connection with the catalyst and initiator system (describedin more detail below) are those olefinic compounds, the polymerizationof which are known to be cationically initiated. Preferably, the olefinpolymerization feeds employed in the present invention are thoseolefinic compounds conventionally used in the preparation of butyl-typerubber polymers. The terpolymers are prepared by reacting a comonomermixture, the mixture having at least (1) a C₄ to C₈ isoolefin monomercomponent such as isobutylene, (2) a styrenic monomer, and (3) amultiolefin monomer component.

The terpolymer of the present invention can be defined by ranges of eachmonomer derived unit. The isoolefin is in a range from at least 70 wt %by weight of the total terpolymer in one embodiment, and at least 80 wt% in another embodiment, and at least 90 wt % in yet another embodiment,and from 70 wt % to 99.5 wt % in yet another embodiment, and 85 to 99.5wt % in another embodiment. The styrenic monomer is present from 0.5 wt% to 30 wt % by weight of the total terpolymer in one embodiment, andfrom 1 wt % to 25 wt % in another embodiment, and from 2 wt % to 20 wt %in yet another embodiment, and from 5 wt % to 20 wt % in yet anotherembodiment. The multiolefin component in one embodiment is present inthe terpolymer from 30 wt % to 0.2 wt % in one embodiment, and from 15wt % to 0.5 wt % in another embodiment. In yet another embodiment, from8 wt % to 0.5 wt % of the terpolymer is multiolefin. Desirableembodiments of terpolymer may include any combination of any upper wt %limit combined with any lower wt % limit by weight of the terpolymer.

The isoolefin may be a C₄ to C₈ compound, in one embodiment selectedfrom isobutylene, isobutene, 2-methyl-1-butene, 3-methyl-1-butene,2-methyl-2-butene, and 4-methyl-1-pentene. The styrenic monomer may beany substituted styrene monomer unit, and desirably is selected fromstyrene, α-methylstyrene or an alkylstyrene (ortho, meta, or para), thealkyl selected from any C₁ to C₅ alkyl or branched chain alkyl. In adesirable embodiment, the styrenic monomer is p-methylstyrene. Themultiolefin may be a C₄ to C₁₄ diene, conjugated or not, in oneembodiment selected from isoprene, butadiene,2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethyl-fulvene, hexadiene,cyclopentadiene, methylcyclopentadiene, and piperylene.

Isomonoolefin, styrene-based monomers, and multiolefin monomers,particularly isobutylene, p-methylstyrene and isoprene, can becopolymerized under cationic conditions. See, for example, WO00/27807and 01/04731; U.S. Pat. Nos. 3,560,458, and 5,162,445. Thecopolymerization is carried out by means of at least one Lewis Acidcatalyst. Desirable catalysts are Lewis Acids based on metals from Group4, 13 and 15 of the Periodic Table of the Elements, including boron,aluminum, gallium, indium, titanium, zirconium, tin, vanadium, arsenic,antimony, and bismuth. In one embodiment, the metals are aluminum, boronand titanium, with aluminum being desirable.

The Group 13 Lewis Acids have the general formula R_(n)MX_(3−n), wherein“M” is a Group 13 metal, R is a monovalent hydrocarbon radical selectedfrom C₁ to C₁₂ alkyl, aryl, arylalkyl, alkylaryl and cycloalkylradicals; and n is an integer from 0 to 3; and X is a halogenindependently selected from fluorine, chlorine, bromine, and iodine,preferably chlorine. The term “arylalkyl” refers to a radical containingboth aliphatic and aromatic structures, the radical being at an alkylposition. The term “alkylaryl” refers to a radical containing bothaliphatic and aromatic structures, the radical being at an arylposition. Nonlimiting examples of these Lewis acids include aluminumchloride, aluminum bromide, boron trifluoride, boron trichloride, ethylaluminum dichloride (EtAlCl₂ or EADC), diethyl aluminum chloride(Et₂AlCl or DEAC), ethyl aluminum sesquichloride (Et_(1.5)AlCl_(1.5) orEASC), trimethyl aluminum, and triethyl aluminum.

The Group 4 Lewis Acids have the general formula MX₄, wherein M is aGroup 4 metal and X is a ligand, preferably a halogen. Nonlimitingexamples include titanium tetrachloride, zirconium tetrachloride, or tintetrachloride.

The Group 15 Lewis Acids have the general formula MX_(y), wherein M is aGroup 15 metal, X is a ligand, preferably a halogen, and y is an integerfrom 3 to 5. Nonlimiting examples include vanadium tetrachloride andantimony pentafluoride. In one embodiment, Lewis acids may be any ofthose useful in cationic polymerization of isobutylene copolymersincluding: AlCl₃, EADC, EASC, DEAC, BF₃, TiCl₄, etc. with EASC and EADCbeing desirable in one embodiment.

Catalyst efficiency (based on Lewis Acid) in a large-scale continuousslurry reactor is preferably maintained between 10000 lb. of polymer/lb.of catalyst and 300 lb. of polymer/lb. of catalyst and desirably in therange of 4000 lb. of polymer/lb. of catalyst to 1000 lb. of polymer/lb.of catalyst by controlling the molar ratio of Lewis Acid to initiator.

According to one embodiment of the invention, the Lewis Acid catalyst isused in combination with an initiator. The initiator may be described bythe formula (A):

wherein X is a halogen, desirably chlorine or bromine; R₁ is selectedfrom hydrogen, C₁ to C8 alkyls, and C₂ to C₈ alkenyls, aryl, andsubstituted aryl; R₃ is selected from C₁ to C₈ alkyls, C₂ to C₈alkenyls, aryls, and substituted aryls; and R₂ is selected from C₄ toC₂₀₀ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls, C₃ to C₁₀cycloalkyls, and groups represented by the following formula (B):

wherein X is a halogen, desirably chlorine or bromine; R₅ is selectedfrom C₁ to C₈ alkyls, and C₂ to C₈ alkenyls; R₆ is selected from C₁ toC₈ alkyls, C₂ to C₈ alkenyls aryls, and substituted aryls; and R₄ isselected from phenylene, biphenyl, α,ω-diphenylalkane and —(CH₂)_(n)—,wherein n is an integer from 1 to 10; and wherein R₁, R₂, and R₃ canalso form adamantyl or bornyl ring systems, the X group being in atertiary carbon position in one embodiment.

As used herein, the term “alkenyl” refers to singly ormultiply-unsaturated alkyl groups such as, for example, C₃H₅ group, C₄H₅group, etc.

Substitution of the above structural formula radical (B) for R₂ informula (A) results in the following formula (C):

wherein X, R₁, R₃, R₄, R₅ and R₆ are as defined above. The compoundsrepresented by structural formula (C) contain two dissociable halides.

Multifunctional initiators are employed where the production of branchedcopolymers is desired, while mono- and di-functional initiators arepreferred for the production of substantially linear copolymers.

In one desirable embodiment, the initiator is an oligomer of isobutyleneas represented in structure (D):

wherein X is a halogen, and the value of m is from 1 to 60, and mixturesthereof. In another embodiment, m is from 2 to 40. This structure isalso described as a tertiary alkyl chloride-terminated polyisobutylenehaving a Mn up to 2500 in one embodiment, and up to 1200 in anotherembodiment.

Non-limiting examples of suitable initiators are cumyl esters ofhydrocarbon acids, and alkyl cumyl ethers, other cumyl compounds and orhalogenated organic compounds, especially secondary or tertiaryhalogenated compounds such as, for example, t-butyl chloride,2-acetyl-2-phenylpropane (cumyl acetate), 2-methoxy-2-phenyl propane(cumylmethyl-ether), 1,4-di(2-methoxy-2-propyl)benzene (di(cumylmethylether)); the cumyl halides, particularly the chlorides, such as, forexample 2-chloro-2-phenylpropane, cumyl chloride(1-chloro-1-methylethyl)benzene), 1,4-di(2-chloro-2-propyl)benzene(di(cumylchloride)), and 1,3,5-tri(2-chloro-2-propyl)benzene(tri(cumylchloride)); the aliphatic halides, particularly the chlorides,such as, for example, 2-chloro-2,4,4-trimethylpentane (“TMPCl”),2-bromo-2,4,4-trimethylpentane (“TMPBr”), and2,6-dichloro-2,4,4,6-tetramethylheptane; cumyl and aliphatic hydroxylssuch as 1,4-di((2-hydroxyl-2-propyl)-benzene),2,6-dihydroxyl-2,4,4,6-tetramethyl-heptane, 1-chloroadamantane and1-chlorobornane, 5-tert-butyl-1,3-di(1-chloro-1-methyl ethyl) benzeneand similar compounds. Other suitable initiators are disclosed in U.S.Pat. Nos. 4,946,899, 3,560,458. These initiators are generally C₅ orgreater tertiary or allylic alkyl or benzylic halides and may includepolyfunctional initiators. Desirable examples of these initiatorsinclude: TMPCl, TMPBr, 2,6-dichloro-2,4,4,6-tetramethylheptane, cumylchloride as well as ‘di-’ and ‘tri-’ cumyl chloride or bromide.

The selected diluent or diluent mixture should provide a diluent mediumhaving some degree of polarity. To fulfil this requirement a mixture ofnonpolar and polar diluent can be used but one or a mixture of polardiluents is preferred. Suitable nonpolar diluent components includeshydrocarbons and preferably aromatic or cyclic hydrocarbons or mixturesthereof. Such compounds include, for instance, methylcyclohexane,cyclohexane, toluene, carbon disulfide and others. Appropriate polardiluents include halogenated hydrocarbons, normal, branched chain orcyclic hydrocarbons. Specific compounds include the preferred liquiddiluents such as ethyl chloride, methylene chloride, methylchloride(chloromethane), CHCl₃, CCl₄, n-butyl chloride, chlorobenzene, and otherchlorinated hydrocarbons. To achieve suitable polarity and solubility,it has been found that if the diluent, or diluent mixture, is a mixtureof polar and nonpolar diluents, the mixture is preferably at least 70%polar component, on a volume basis.

The relative polarity of the diluent can be described in terms of thedielectric constant of the diluent. In one embodiment, the diluent has adielectric constant (as measured at from 20 to 25° C.) of greater than5, and greater than 6 in another embodiment. In yet another embodiment,the dielectric constant of the diluent is greater than 7, and greaterthan 8 in yet another embodiment. In a desirable embodiment, thedielectric constant is greater than 9. Examples of dielectric constants(20-25° C.) for single diluents are: chloromethane (10), dichloromethane(8.9), carbon disulfide (2.6), toluene (2.4), and cyclohexane (2.0) asfrom CRC HANDBOOK OF CHEMISTRY AND PHYSICS 6-151 to 6-173 (D. R. Line,ed., 82 ed. CRC Press 2001).

As is typically the case, product molecular weights are determined bytemperature, monomer and initiator concentration, the nature of thereactants, and similar factors. Consequently, different reactionconditions will produce products of different molecular weights and/ordifferent monomer composition in the terpolymers. Synthesis of thedesired reaction product will be achieved, therefore, through monitoringthe course of the reaction by the examination of samples takenperiodically during the reaction, a technique widely employed in the artand shown in the examples or by sampling the effluent of a reactor.

The present invention is not herein limited by the method of making theterpolymer. The terpolymer can be produced using batch polymerization orcontinuous slurry polymerization, for example, and on any volume scale.The reactors that may be utilized in the practice of the presentinvention include any conventional reactors and equivalents thereof.Preferred reactors include those capable of performing a continuousslurry process, such as disclosed in U.S. Pat. No. 5,417,930. Thereactor pump impeller can be of the up-pumping variety or thedown-pumping variety. The reactor will contain sufficient amounts of thecatalyst system of the present invention effective to catalyze thepolymerization of the monomer containing feed-stream such that asufficient amount of polymer having desired characteristics is produced.The feed-stream in one embodiment contains a total monomer concentrationgreater than 30 wt % (based on the total weight of the monomers,diluent, and catalyst system), greater than 35 wt % in anotherembodiment. In yet another embodiment, the feed-stream will contain from35 wt % to 50 wt % monomer concentration based on the total weight ofmonomer, diluent, and catalyst system. The bulk-phase, or phase in whichthe monomers and catalyst contact one another in order to react and forma polymer, may also have the same monomer concentrations.

The feed-stream or bulk-phase is substantially free from silica cationproducing species in one embodiment of the invention. By substantiallyfree of silica cation producing species, it is meant that there is nomore than 0.0005 wt % based on the total weight of the monomers ofsilica species in the feed stream or bulk-phase. Typical examples ofsilica cation producing species are halo-alkyl silica compounds havingthe formula R₁R₂R₃SiX or R₁R₂SiX₂, etc., wherein each “R” is an alkyland “X” is a halogen.

The reaction conditions are typically such that desirable temperature,pressure and residence time are effective to maintain the reactionmedium in the liquid state and to produce the desired polymers havingthe desired characteristics. The monomer feed-stream is typicallysubstantially free of any impurity which is adversely reactive with thecatalyst under the polymerization conditions. For example, the monomerfeed preferably should be substantially free of bases (such as K₂O,NaOH, CaCO₃ and other hydroxides, oxides and carbonates),sulfur-containing compounds (such as H₂S, COS, and organo-mercaptans,e.g., methyl mercaptan, ethyl mercaptan), N-containing compounds, oxygencontaining bases such as alcohols and the like. By “substantially free”,it is meant that the above mentioned species are present, if at all, toan extent no greater than 0.0005 wt %.

In one embodiment, the ratio of monomers contacted together in thepresence of the catalyst system ranges from 98 wt % isoolefin, 1.5 wt %styrenic monomer, and 0.5 wt % multiolefin (“98/1.5/0.5”), to a 50/25/25ratio by weight of the total amount of monomers. For example, theisoolefin monomer may be present from 50 wt % to 98 wt % by total weightof the monomers in one embodiment, and from 70 wt % to 90 wt % inanother embodiment. The styrenic monomers may be present from 1.5 wt %to 25 wt % by total weight of the monomers in one embodiment, and from 5wt % to 15 wt % in another embodiment. The multiolefin may be presentfrom 0.5 wt % to 25 wt % by total weight of the monomers in oneembodiment, and from 2 wt % to 10 wt % in another embodiment, and from 3wt % to 5 wt % in yet another embodiment.

The polymerization reaction temperature is conveniently selected basedon the target polymer molecular weight and the monomer to be polymerizedas well as standard process variable and economic considerations, forexample, rate, temperature control, etc. The temperature for thepolymerization is between −10° C. and the freezing point of thepolymerization system in one embodiment, and from −25° C. to −120° C. inanother embodiment. In yet another embodiment, the polymerizationtemperature is from −40° C. to −100° C., and from −70° C. to −100° C. inyet another embodiment. In yet another desirable embodiment, thetemperature range is from −80° C. to −99° C. The temperature is chosensuch that the desired polymer molecular weight is achieved, the range ofwhich may comprise any combination of any upper limit and any lowerlimit disclosed herein.

The catalyst (Lewis Acid) to monomer ratio utilized are thoseconventional in this art for carbocationic polymerization processes.Particular monomer to catalyst ratios are desirable in continuous slurryor solution processes, wherein most any ratio is suitable for small,laboratory scale polymer synthesis. In one embodiment of the invention,the catalyst (Lewis acid) to monomer mole ratios will be from 0.10 to20, and in the range of 0.5 to 10 in another embodiment. In yet anotherdesirable embodiment, the ratio of Lewis Acid to initiator is from 0.75to 2.5, or from 1.25 to 1.5 in yet another desirable embodiment. Theoverall concentration of the initiator is from 50 to 300 ppm within thereactor in one embodiment, and from 100 to 250 ppm in anotherembodiment. The concentration of the initiator in the catalyst feedstream is from 500 to 3000 ppm in one embodiment, and from 1000 to 2500ppm in another embodiment. Another way to describe the amount ofinitiator in the reactor is by its amount relative to the polymer. Inone embodiment, there is from 0.25 to 5.0 moles polymer/mole initiator,and from 0.5 to 3.0 mole polymer/mole initiator in another embodiment.

It is known that chlorine or bromine can react with unsaturation of themultiolefin derived units (e.g., isoprene residue units) rapidly to formhalogenated polymer. Methods of halogenating polymers such as butylpolymers are disclosed in U.S. Pat. Nos. 2,964,489; 2,631,984;3,099,644; 4,254,240; 4,554,326; 4,681,921; 4,650,831; 4,384,072;4,513,116; and 5,681,901. Typical halogenation processes for makinghalobutyl rubbers involves injection of a desirable amount of chlorineor bromine into the cement (solution) of butyl rubber with the reactantsbeing mixed vigorously in the halogenation reactor with a rather shortresident time, typically less than 1 minute, following by neutralizationof the HCl or HBr and any unreacted halogen. It is also well known inthe art that the specific structure of the halogenated butyl rubber iscomplicated and is believed to depend on the halogenation condition.Most commercial bromobutyl rubbers are made under the condition that theformation of “structure III” type brominated moiety is minimized, as isthe brominated terpolymer of the present invention. See, for example,Anthony Jay Dias in 5 POLYMERIC MATERIALS ENCYCLOPEDIA 3485-3492 (JosephC. Salamone, ed., CRC Press 1996). That typically means the absence offree radical sources such as light or high temperature. Alternativelythe halogenation can be carried out in polymer melt in an extruder orother rubber mixing devices in the absence of solvent.

The final level of halogen on the halogenated terpolymer, includinghalogen located on the polymer backbone and the styrenic moietiesincorporated therein, depends on the application and desirable curingperformance. The halogen content of a typical halogenated terpolymer ofthe present invention ranges from 0.05 wt % to 5 wt % by weight of theterpolymer in one embodiment, and from 0.2 wt % to 3 wt % in anotherembodiment, and from 0.8 wt % to 2.5 wt % in yet another embodiment. Inyet another embodiment, the amount of halogen present on the terpolymeris less than 10 wt %, and less than 8 wt % in another embodiment, andless than 6 wt % in yet another embodiment. Stated another way, theamount of halogen incorporated into the terpolymer is from less than 5mole % in one embodiment, and from 0.1 to 2.5 mole % relative to thetotal moles of monomer derived units in the terpolymer in anotherembodiment, and from 0.2 to 2 mole % in another embodiment, and from 0.4to 1.5 mole % in yet another embodiment. A desirable level ofhalogenation may include any combination of any upper wt % or mole %limit with any lower wt % or mole % limit.

In another embodiment, the halogen content on the backbone (isoprenederived units) of a typical halogenated terpolymer of the presentinvention ranges from 0.05 wt % to 5 wt % by weight of the terpolymer inone embodiment, and from 0.2 wt % to 3 wt % in another embodiment, andfrom 0.8 wt % to 2.5 wt % in yet another embodiment. In yet anotherembodiment, the amount of halogen present on the terpolymer is less than10 wt %, and less than 8 wt % in another embodiment, and less than 6 wt% in yet another embodiment. Stated another way, the amount of halogenincorporated into the terpolymer is from less than 5 mole % in oneembodiment, and from 0.1 to 2.5 mole % relative to the total moles ofmonomer derived units in the terpolymer in another embodiment, and from0.2 to 2 mole % in another embodiment, and from 0.4 to 1.5 mole % in yetanother embodiment. A desirable level of halogenation may include anycombination of any upper wt % or mole % limit with any lower wt % ormole % limit.

In yet another embodiment, the halogen content on the styrenic moieties,for example, p-methylstyrene (thus forming p-halomethylstyrene), wasfrom 0.05 wt % to 5 wt %, and from 0.2 to 3 wt % in yet anotherembodiment, and from 0.2 wt % to 2 wt % in yet another embodiment, andfrom 0.2 wt % to 1 wt % in yet another embodiment, and from 0.5 wt % to2 wt % in yet another embodiment.

The molecular weight, number average molecular weight, etc. of theterpolymer depends upon the reaction conditions employed, such as, forexample, the amount of multiolefin present in the monomer mixtureinitially, the ratios of Lewis Acid to initiator, reactor temperature,and other factors. The terpolymer of the present invention has a numberaverage molecular weight (Mn) of up to 1,000,000 in one embodiment, andup to 800,000 in another embodiment. In yet another embodiment, theterpolymer has an Mn of up to 400,000, and up to 300,000 in yet anotherembodiment, and up to 180,000 in yet another embodiment. The Mn value ofthe terpolymer is at least 80,000 in another embodiment, and at least100,000 in yet another embodiment, and at least 150,000 in yet anotherembodiment, and at least 300,000 in yet another embodiment. A desirablerange in the Mn value of the terpolymer can be any combination of anyupper limit and any lower limit.

The terpolymer has a weight average molecular weight (Mw) of up to2,0000,000 in one embodiment, and up to 1,000,000 in another embodiment,and up to 800,000 in yet another embodiment, and up to 500,000 in yetanother embodiment. The Mw value for the terpolymer is at least 80,000in yet another embodiment, and at least 100,000 in another embodiment,and at least 150,000 in yet another embodiment, and at least 200,000 inyet another embodiment. The desirable range in the Mw value of theterpolymer can be any combination of any upper limit and any lowerlimit.

The peak molecular weight value (Mp) of the terpolymer is at least2,000,000 in one embodiment, 100,000 another one embodiment, and atleast 150,000 in another embodiment, and at least 300,000 in yet anotherembodiment. The Mp value of the terpolymer is up to 600,000 in anotherembodiment, and up to 400,000 in yet another embodiment. The desirablerange in the Mp value of the terpolymer can be any combination of anyupper limit and any lower limit.

The terpolymer has a molecular weight distribution (Mw/Mn, or MWD) ofless than 7.0 in one embodiment, and less than 4.0 in anotherembodiment, and from 1.5 to 3.8 in yet another embodiment. In yetanother embodiment, the MWD value is from 2.0 to 3.5. The value MWD canbe any combination of any upper limit value and any lower limit value.

Finally, the terpolymer of the invention has a Mooney viscosity (1+8,125° C.) of from 20 to 60 MU in one embodiment, and from 25 to 70 MU inanother embodiment, and from 30 to 50 in yet another embodiment, andfrom 50 to 70 MU in yet another embodiment.

The terpolymer and/or halogenated terpolymer may be part of acomposition including other components such as one or more secondaryrubber components, a cure system, especially a sulfur cure system, atleast one filler such as carbon black or silica, and other minorcomponents common in the rubber compounding arts. The terpolymer orhalogenated terpolymer may be present from 5 phr to 100 phr in thecomposition one embodiment, from 20 phr to 100 phr in the composition inanother embodiment, and from 30 phr to 90 phr in yet another embodiment,and from 40 phr to 80 phr in yet another embodiment, and from 20 phr to50 phr in yet another embodiment, and from 15 phr to 55 phr in yetanother embodiment, and up to 100 phr in another embodiment.

Secondary Rubber Component

A secondary rubber component may be present in compositions of thepresent invention. These rubbers include, but are not limited to,natural rubbers, polyisoprene rubber, poly(styrene-co-butadiene) rubber(SBR), polybutadiene rubber (BR), poly(isoprene-co-butadiene) rubber(IBR), styrene-isoprene-butadiene rubber (SIBR), ethylene-propylenerubber (EPM), ethylene-propylene-diene rubber (EPDM), polysulfide,nitrile rubber, propylene oxide polymers, star-branched butyl rubber andhalogenated star-branched butyl rubber, brominated butyl rubber,chlorinated butyl rubber, star-branched polyisobutylene rubber,star-branched brominated butyl (polyisobutylene/isoprene copolymer)rubber; poly(isobutylene-co-p-methylstyrene) and halogenatedpoly(isobutylene-co-p-methylstyrene), such as, for example, terpolymersof isobutylene derived units, p-methylstyrene derived units, andp-bromomethylstyrene derived units, and mixtures thereof.

A desirable embodiment of the secondary rubber component present isnatural rubber. Natural rubbers are described in detail by Subramaniamin RUBBER TECHNOLOGY 179-208 (Maurice Morton, Chapman & Hall 1995).Desirable embodiments of the natural rubbers of the present inventionare selected from Malaysian rubber such as SMR CV, SMR 5, SMR 10, SMR20, and SMR 50 and mixtures thereof, wherein the natural rubbers have aMooney viscosity at 100° C. (ML 1+4) of from 30 to 120, more preferablyfrom 40 to 65. The Mooney viscosity test referred to herein is inaccordance with ASTM D-1646.

Polybutadiene (BR) rubber is another desirable secondary rubber usefulin the composition of the invention. The Mooney viscosity of thepolybutadiene rubber as measured at 100° C. (ML 1+4) may range from 35to 70, from 40 to about 65 in another embodiment, and from 45 to 60 inyet another embodiment. Some commercial examples of these syntheticrubbers useful in the present invention are NATSYN™ (Goodyear ChemicalCompany), and BUDENE™ 1207 or BR 1207 (Goodyear Chemical Company). Adesirable rubber is high cis-polybutadiene (cis-BR). By“cis-polybutadiene” or “high cis-polybutadiene”, it is meant that1,4-cis polybutadiene is used, wherein the amount of cis component is atleast 95%. An example of high cis-polybutadiene commercial products usedin the composition BUDENE™ 1207.

Rubbers of ethylene and propylene derived units such as EPM and EPDM arealso suitable as secondary rubbers. Examples of suitable comonomers inmaking EPDM are ethylidene norbornene, 1,4-hexadiene, dicyclopentadiene,as well as others. These rubbers are described in RUBBER TECHNOLOGY260-283 (1995). A suitable ethylene-propylene rubber is commerciallyavailable as VISTALON™ (ExxonMobil Chemical Company, Houston Tex.).

In another embodiment, the secondary rubber is a halogenated rubber aspart of the terpolymer composition. The halogenated butyl rubber isbrominated butyl rubber, and in another embodiment is chlorinated butylrubber. General properties and processing of halogenated butyl rubbersis described in THE VANDERBILT RUBBER HANDBOOK 105-122 (Robert F. Ohmed., R. T. Vanderbilt Co., Inc. 1990), and in RUBBER TECHNOLOGY 311-321(1995). Butyl rubbers, halogenated butyl rubbers, and star-branchedbutyl rubbers are described by Edward Kresge and H. C. Wang in 8KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY 934-955 (John Wiley &Sons, Inc. 4th ed. 1993).

The secondary rubber component of the present invention includes, but isnot limited to at least one or more of brominated butyl rubber,chlorinated butyl rubber, star-branched polyisobutylene rubber,star-branched brominated butyl (polyisobutylene/isoprene copolymer)rubber; halogenated poly(isobutylene-co-p-methylstyrene), such as, forexample, terpolymers of isobutylene derived units, p-methylstyrenederived units, and p-bromomethylstyrene derived units (BrIBMS), and thelike halomethylated aromatic interpolymers as in U.S. Pat. Nos.5,162,445; 4,074,035; and 4,395,506; halogenated isoprene andhalogenated isobutylene copolymers, polychloroprene, and the like, andmixtures of any of the above. Some embodiments of the halogenated rubbercomponent are also described in U.S. Pat. Nos. 4,703,091 and 4,632,963.

In one embodiment of the invention, a so called semi-crystallinecopolymer (“SCC”) is present as the secondary “rubber” component.Semi-crystalline copolymers are described in WO00/69966. Generally, theSCC is a copolymer of ethylene or propylene derived units and α-olefinderived units, the α-olefin having from 4 to 16 carbon atoms in oneembodiment, and in another embodiment the SCC is a copolymer of ethylenederived units and α-olefin derived units, the α-olefin having from 4 to10 carbon atoms, wherein the SCC has some degree of crystallinity. In afurther embodiment, the SCC is a copolymer of 1-butene derived units andanother α-olefin derived unit, the other α-olefin having from 5 to 16carbon atoms, wherein the SCC also has some degree of crystallinity. TheSCC can also be a copolymer of ethylene and styrene.

The secondary rubber component of the elastomer composition may bepresent in a range from up to 90 phr in one embodiment, from up to 50phr in another embodiment, from up to 40 phr in another embodiment, andfrom up to 30 phr in yet another embodiment. In yet another embodiment,the secondary rubber is present from at least 2 phr, and from at least 5phr in another embodiment, and from at least 5 phr in yet anotherembodiment, and from at least 10 phr in yet another embodiment. Adesirable embodiment may include any combination of any upper phr limitand any lower phr limit. For example, the secondary rubber, eitherindividually or as a blend of rubbers such as, for example NR and BR,may be present from 5 phr to 90 phr in one embodiment, and from 10 to 80phr in another embodiment, and from 30 to 70 phr in yet anotherembodiment, and from 40 to 60 phr in yet another embodiment, and from 5to 50 phr in yet another embodiment, and from 5 to 40 phr in yet anotherembodiment, and from 20 to 60 phr in yet another embodiment, and from 20to 50 phr in yet another embodiment, the chosen embodiment dependingupon the desired end use application of the composition.

Filler

Elastomeric compositions suitable for an air barrier of the inventionmay include one or more filler components such as calcium carbonate,clay, mica, silica and silicates, talc, titanium dioxide, starch andother organic fillers such as wood flower, and carbon black. In oneembodiment, the filler is carbon black or modified carbon black. In oneembodiment, the filler is reinforcing grade carbon black present at alevel of from 10 to 150 phr, preferably 10 to 100 phr, of thecomposition, preferably from 30 to 120 phr, more preferably 40 to 80phr. Useful grades of carbon black are described in RUBBER TECHNOLOGY59-85 (1995) and range from N110 to N990. More desirably, embodiments ofthe carbon black useful in, for example, tire treads are N229, N351,N339, N220, N234 and N110 provided in ASTM (D3037, D1510, and D3765).Embodiments of the carbon black useful in, for example, sidewalls intires, are N330, N351, N550, N650, N660, and N762. Embodiments of thecarbon black useful in, for example, innerliners or innertubes are N550,N650, N660, N762, N990, and Regal 85 (Cabot Corporation, Alpharetta,Ga.) and the like.

Modified carbon blacks may also be suitable as a filler. Such “modifiedcarbon black” is disclosed in, for example, U.S. Pat. Nos. 3,620,792;5,900,029; and 6,158,488. For example, the modified carbon black maycomprise carbon black that has been subjected to treatment with a gassuch as a nitrogen oxide, ozone, or other gas which may impart improvedproperties to the surface of the carbon black. The modified carbon blackmay also comprise, for example, a carbon black that has been contactedwith a silanol-containing compound and/or a hydrocarbon radical such asan alkyl, aryl, alkylaryl and arylalkyl. The modified carbon blackcontacted with a silanol-containing compound can be prepared, forexample, by contacting an organosilane such as an alkyl alkoxy silanewith carbon black at an elevated temperature. Representativeorganosilanes include tetraakoxysilicates such as tetraethyoxysilicate.Alternatively, the modified carbon black can be prepared by co-fuming anorganosilane and an oil in the presence of the carbon black at anelevated temperature. In yet another example preparing a modified carbonblack, a diazonium salt can be contacted with the carbon black eitherwith or without an electron source or with or without a protic solvent.Diazonium salts are known in the art and may be generated by contactinga primary amine, a nitrile and an acid (proton donor). The nitrile maybe any metal nitrile, desirably a lithium nitrile, sodium nitrile,potassium nitrile, zinc nitrile, or some combination thereof, or anyorganic nitrile such as isoamylnitrile or ethylnitrile, or somecombination of these.

Exfoliated clays may also be present in the composition. These clays,also referred to as “nanoclays”, are well known, and their identity,methods of preparation and blending with polymers is disclosed in, forexample, JP2000109635; JP2000109605; JP11310643; DE19726278; WO98/53000;U.S. Pat. Nos. 5,091,462; 4,431,755; 4,472,538; and 5,910,523. Swellablelayered clay materials suitable for the purposes of this inventioninclude natural or synthetic phyllosilicates, particularly smectic clayssuch as montmorillonite, nontronite, beidellite, volkonskoite, laponite,hectorite, saponite, sauconite, magadite, kenyaite, stevensite and thelike, as well as vermiculite, halloysite, aluminate oxides, hydrotalciteand the like. These layered clays generally comprise particlescontaining a plurality of silicate platelets having a thickness of from4-20 Å in one embodiment, 8-12 Å in another embodiment, bound togetherand contain exchangeable cations such as Na⁺, Ca⁺², K⁺ or Mg³⁰ ² presentat the interlayer surfaces.

The layered clay may be intercalated and exfoliated by treatment withorganic molecules (swelling agents) capable of undergoing ion exchangereactions with the cations present at the interlayer surfaces of thelayered silicate. Suitable swelling agents include cationic surfactantssuch as ammonium, alkylamines or alkylammonium (primary, secondary,tertiary and quaternary), phosphonium or sulfonium derivatives ofaliphatic, aromatic or arylaliphatic amines, phosphines and sulfides.Desirable amine compounds (or the corresponding ammonium ion) are thosewith the structure R₁R₂R₃N, wherein R₁, R₂, and R₃ are C₁ to C₂₀ alkylsor alkenes which may be the same or different. In one embodiment, theexfoliating agent is a long chain tertiary amine, wherein at least R₁ isa C₁₄ to C₂₀ alkyl or alkene.

Another class of swelling agents include those which can be covalentlybonded to the interlayer surfaces. These include polysilanes of thestructure—Si(R′)₂R² where R′ is the same or different at each occurrenceand is selected from alkyl, alkoxy or oxysilane and R² is an organicradical compatible or soluble with the matrix polymer of the composite.

Other suitable swelling agents include protonated amino acids and saltsthereof containing 2-30 carbon atoms such as 12-aminododecanoic acid,epsilon-caprolactam and like materials. Suitable swelling agents andprocesses for intercalating layered silicates are disclosed in U.S. Pat.Nos. 4,472,538; 4,810,734; 4,889,885; as well as WO92/02582.

In one embodiment of the invention, the exfoliating additive is combinedwith the halogenated terpolymer. In one embodiment, the additiveincludes all primary, secondary and tertiary amines and phosphines;alkyl and aryl sulfides and thiols; and their polyfunctional versions.Desirable additives include: long-chain tertiary amines such asN,N-dimethyl-octadecylamine, N,N-diociadecyl-methylamine, so calleddihydrogenated tallowalkyl-methylamine and the like, andamine-terminated polytetrahydrofuran; long-chain thiol and thiosulfatecompounds like hexamethylene sodium thiosulfate. In another embodimentof the invention, improved interpolymer impermeability is achieved bythe presence of polyfunctional curatives such as hexamethylenebis(sodium thiosulfate) and hexamethylene bis(cinnamaldehyde).

In yet another embodiment of the composition, the filler may be amineral filler such as silica. A description of desirable mineralfillers is described by Walter H. Waddell and Larry R. Evans in RUBBERTECHNOLOGY, COMPOUNDING AND TESTING FOR PERFORMANCE 325-332 (John S.Dick, ed. Hanser Publishers 2001). Such mineral fillers include calciumcarbonate and other alkaline earth and alkali metal carbonates, bariumsulfate and other metal sulfates, ground crystalline silica, biogenicsilica, such as from dolomite, kaolin clay and other alumina-silicateclays, talc and other magnesium-silica compounds, alumina, metal oxidessuch as titanium oxide and other Group 3-12 metal oxides, any of whichnamed above can be precipitated by techniques known to those skilled inthe art. Particularly desirable mineral fillers include precipitatedsilicas and silicates. Other suitable non-black fillers and processingagents (e.g., coupling agents) for these fillers are disclosed in theBLUE BOOK 275-302, 405-410 (Lippincott & Peto Publications, RubberWorld2001).

When such mineral fillers are present, it is desirable to also includeorganosilane coupling agents. The coupling agent is typically abifunctional organosilane cross-linking agent. By an “silane couplingagent” is meant any silane coupled filler and/or cross-linking activatorand/or silane reinforcing agent known to those skilled in the artincluding, but not limited to, vinyl triethoxysilane,vinyl-tris-(beta-methoxyethoxy)silane,methacryloylpropyltrimethoxysilane, gamma-amino-propyl triethoxysilane(sold commercially as A1100 by Witco),gamma-mercaptopropyltrimethoxysilane (A189 by Witco) and the like, andmixtures thereof. In a preferred embodiment,bis-(3(triethoxysilyl)-propyl)-tetrasulfane (sold commercially as Si69by Degussa AG, Germany) is employed. Preferably, theorganosilane-coupling agent composes from 2 to 15 weight percent, basedon the weight of filler, of the elastomeric composition in oneembodiment. More preferably, it composes from 4 to 12 weight percent ofthe filler in yet another embodiment.

The filler component of the elastomer composition may be present in arange from up to 120 phr in one embodiment, from up to 100 phr inanother embodiment, and from up to 60 phr in yet another embodiment. Inyet another embodiment, the filler is present from 5 phr to 80 phr, from50 phr to 80 phr in yet another embodiment, from 20 phr to 80 phr in yetanother embodiment, from 10 phr to 70 phr in yet another embodiment,from 50 phr to 70 phr in yet another embodiment, and from 60 phr to 90phr in yet another embodiment, wherein a desirable range can by anycombination of any upper phr limit and any lower phr limit.

Curing Agents and Accelerators

The compositions produced in accordance with the present inventiontypically contain other components and additives customarily used inrubber mixes, such as pigments, accelerators, cross-linking and curingmaterials, antioxidants, antiozonants, and fillers.

Generally, polymer compositions, for example, those used to producetires, are crosslinked. It is known that the physical properties,performance characteristics, and durability of vulcanized rubbercompounds are directly related to the number (crosslink density) andtype of crosslinks formed during the vulcanization reaction. (See, e.g.,W. Helt et al., The Post Vulcanization Stabilization for NR, RUBBERWORLD 18-23 (1991). Cross-linking and curing agents include sulfur, zincoxide, and fatty acids. Peroxide cure systems may also be used.

More particularly, in a desirable embodiment of the composition of theinvention, a “sulfur cure system” is present in the composition. Thesulfur cure system of the present invention includes at least one oremore sulfur compounds such as elemental sulfur, and may includesulfur-based accelerators. Generally, the terpolymer compositions mayalso include other curative components such as, for example sulfur,metal oxides (e.g., zinc oxide), organometallic compounds, radicalinitiators, etc. followed by heating. In particular, the following arecommon curatives that will function in the present invention: ZnO, CaO,MgO, Al₂O₃, CrO₃, FeO, Fe₂O₃, and NiO. These metal oxides can be used inconjunction with a corresponding metal complex, or with a correspondingagent such as a C₆ to C₃₀ fatty acid such as stearic acid, etc. (e.g.,Zn(Stearate)₂, Ca(Stearate)₂, Mg(Stearate)₂, and Al(Stearate)₃), andeither a sulfur compound or an alkylperoxide compound. (See also,Formulation Design and Curing Characteristics of NBR Mixes for Seals,RUBBER WORLD 25-30 (1993). This method may be accelerated and is oftenused for the vulcanization of elastomer compositions. The sulfur curesystem of the present invention includes at least sulfur, typicallyelemental sulfur, and may also include the metal oxides, acceleratorsand phenolic resins disclosed herein.

Accelerators include amines, guanidines, thioureas, thiazoles, thiurams,sulfenamides, sulfenimides, thiocarbamates, xanthates, and the like.Acceleration of the cure process may be accomplished by adding to thecomposition an amount of the accelerant. The mechanism for acceleratedvulcanization of natural rubber involves complex interactions betweenthe curative, accelerator, activators and polymers. Ideally, all of theavailable curative is consumed in the formation of effective crosslinkswhich join together two polymer chains and enhance the overall strengthof the polymer matrix. Numerous accelerators are known in the art andinclude, but are not limited to, the following: stearic acid, diphenylguanidine (DPG), tetramethylthiuram disulfide (TMTD),4,4′-dithiodimorpholine (DTDM), tetrabutylthiuram disulfide (TBTD),2,2′-benzothiazyl disulfide (MBTS), hexamethylene-1,6-bisthiosulfatedisodium salt dihydrate, 2-(morpholinothio) benzothiazole (MBS or MOR),compositions of 90% MOR and 10% MBTS (MOR 90),N-tertiarybutyl-2-benzothiazole sulfenamide (TBBS), and N-oxydiethylenethiocarbamyl-N-oxydiethylene sulfonamide (OTOS), zinc 2-ethyl hexanoafe(ZEH), N,N′-diethyl thiourea.

The compositions of the invention may also include processing oils andresins such as paraffinic, polybutene, naphthenic or aliphatic resinsand oils. Processing aids include, but are not limited to, plasticizers,tackifiers, extenders, chemical conditioners, homogenizing agents andpeptizers such as mercaptans, petroleum and vulcanized vegetable oils,waxes, resins, rosins, and the like. The aid is typically present from 1to 70 phr in one embodiment, from 5 to 60 phr in another embodiment, andfrom 10 to 50 phr in yet another embodiment. Some commercial examples ofprocessing aids are SUNDEX™ (Sun Chemicals), FLEXON™ and PARAPOL™(ExxonMobil Chemical), and CALSOL™ (R. E. Carroll). Other suitableadditives are described by Howard L. Stevens in RUBBER TECHNOLOGY 20-58(1995), especially in Tables 2.15 and 2.18.

In one embodiment of the invention, at least one curing agent(s) ispresent from 0.2 to 15 phr, and from 0.5 to 10 phr in anotherembodiment, and from 2 phr to 8 phr in yet another embodiment. Curingagents include those components described above that facilitate orinfluence the cure of elastomers, such as metals, accelerators, sulfur,peroxides, and other agents common in the art.

The compositions may be vulcanized (cured) by any suitable means such asby subjecting them using heat or radiation according to any conventionalvulcanization process. The amount of heat or radiation (“heat”) is thatrequired to affect a cure in the composition, and the invention is notherein limited to the method and amount of heat required to cure thecomposition in forming a stock material or article. Typically, thevulcanization is conducted at a temperature ranging from about 100° C.to about 250° C. in one embodiment, from 150° C. to 200° C. in anotherembodiment, for about 1 to 150 minutes.

Suitable elastomeric compositions for such articles as tire innerlinersor innertubes may be prepared by using conventional mixing techniquesincluding, e.g., kneading, roller milling, extruder mixing, internalmixing (such as with a Banbury™ mixer) etc. The sequence of mixing andtemperatures employed are well known to the skilled rubber compounder,the objective being the dispersion of fillers, activators and curativesin the polymer matrix without excessive heat buildup. A useful mixingprocedure utilizes a Banbury™ mixer in which the polymer rubber, carbonblack and plasticizer are added and the composition mixed for thedesired time or to a particular temperature to achieve adequatedispersion of the ingredients. Alternatively, the rubber and a portionof the carbon black (e.g., one-third to two thirds) is mixed for a shorttime (e.g., about 1 to 3 minutes) followed by the remainder of thecarbon black and oil. Mixing is continued for about 1 to 10 minutes athigh rotor speed during which time the mixed components reach atemperature of about 140° C. Following cooling, the components are mixedin a second step on a rubber mill or in a Banbury™ mixer during whichthe curing agent and optional accelerators, are thoroughly and uniformlydispersed at relatively low temperature, e.g., about 80° C. to about105° C., to avoid premature curing of the composition. Variations inmixing will be readily apparent to those skilled in the art and thepresent invention is not limited to any specific mixing procedure. Themixing is performed to disperse all components of the compositionthoroughly and uniformly.

An innerliner stock is then prepared by calendering or extruding thecompounded rubber composition into a sheet having a thickness of roughly40 to 100 mil gauge and cutting the sheet material into strips ofappropriate width and length for innerliner applications in the tirebuilding operation. The liner can then be cured while in contact withthe tire carcass and/or sidewall in which it is placed.

An innertube stock is prepared by extruding the compounded rubbercomposition into a tubular shape having a thickness of from 50 to 150mil gauge and cutting the extruded material into a length of appropriatesize. The tubes of extruded material are then second cut and the endsspliced together to form the green tube. The tube is then cured to formthe finished innertube either by heating from 25° C. to 250° C., orexposure to radiation, or by other techniques known to those skilled inthe art.

Test Methods

Cure properties were measured using a MDR 2000 at the indicatedtemperature and 0.5 degree arc. Test specimens were cured at theindicated temperature, typically from 150° C. to 160° C., for a time (inminutes) corresponding to T90+ appropriate mold lag. When possible,standard ASTM tests were used to determine the cured compound physicalproperties. Stress/strain properties (tensile strength, elongation atbreak, modulus values, energy to break) were measured at roomtemperature using an Instron 4202 or Instron 4204. Shore A hardness wasmeasured at room temperature by using a Zwick Duromatic. Abrasion losswas determined at room temperature by weight difference by using anAPH-40 Abrasion Tester with rotating sample holder (5 N counter balance)and rotating drum. Weight losses were indexed to that of the standardDIN compound with lower losses indicative of a higher DIN abrasionresistance index. The weight losses can be measured with an error of±5%.

Temperature-dependent (−80° C. to 60° C.) dynamic properties (G*, G′, G″and tangent delta) were obtained using a Rheometrics ARES. A rectangulartorsion sample geometry was tested at 1 or 10 Hz and 2% strain. Thetemperature-dependent tangent delta curve (such as generated in, e.g.,FIG. 1) maximizes at a temperature affording information used to predicttire performance. The tangent delta values are measured with an error of±5%, while the temperature is measured with an error of ±2° C. Values ofG″ or tangent delta measured in the range from −10° C. to 10° C. inlaboratory dynamic testing can be used as predictors of tire wettraction, while values of from −20° C. to −40° C. are used to predictwinter traction. Values of tangent delta measured in the range of from50° C. to 70° C. in laboratory dynamic testing can be used as predictorsof tire rolling resistance.

Gel permeation chromatography was used to determine molecular weightdata for the terpolymers. The values of number average molecular weight(Mn), weight average molecular weight (Mw) and peak molecular weight(Mp) obtained have an error of ±20%. The techniques for determining themolecular weight and molecular weight distribution (MWD) are generallydescribed in U.S. Pat. No. 4,540,753 to Cozewith et al. and referencescited therein, and in Verstrate et al., 21 MACROMOLECULES 3360 (1988).In a typical measurement, a 3-column set is operated at 30° C. Theelution solvent used may be stabilized tetrahydrofuran (THF), or1,2,4-trichlorobenzene (TCB). The columns are calibrated usingpolystyrene standards of precisely known molecular weights. Acorrelation of polystyrene retention volume obtained from the standards,to the retention volume of the polymer tested yields the polymermolecular weight.

¹H- and decoupled ¹³C-NMR spectroscopic analyses were run in eitherCDCl₃ or toluene-d₈ at ambient temperature using a field strength of 250MHz (¹³C-63 MHz) or in tetrachloroethane-d₂ at 120° C. using a fieldstrength of 500 MHz (¹³C-125 MHz) depending upon the sample'ssolubility. Incorporation (mol %) of isobutylene and isoprene into theterpolymers of all examples was determined by comparison the integrationof the methyl proton resonances with those of the methylene protonresonances and resonances specific for the PMS.

Oxygen permeability was measured using a MOCON OxTran Model 2/61operating under the principle of dynamic measurement of oxygen transportthrough a thin film as published by R. A. Pasternak et al. in 8 JOURNALOF POLYMER SCIENCE: PART A-2 467 (1970). The units of measure arecc-mil/m ²-day-mmHg. Generally, the method is as follows: flat film orrubber samples are clamped into diffusion cells which are purged ofresidual oxygen using an oxygen free carrier gas at 60° C. The carriergas is routed to a sensor until a stable zero value is established. Pureoxygen or air is then introduced into the outside of the chamber of thediffusion cells. The oxygen diffusing through the film to the insidechamber is conveyed to a sensor which measures the oxygen diffusionrate.

Air permeability was tested by the following method. Thin, vulcanizedtest specimens from the sample compositions were mounted in diffusioncells and conditioned in an oil bath at 65° C. The time required for airto permeate through a given specimen is recorded to determine its airpermeability. Test specimens were circular plates with 12.7-cm diameterand 0.38-mm thickness. The error (2σ) in measuring air permeability is±0.245 (×10⁸) units. Other test methods are described in Table 2.

Adhesion to SBR Test. This test method, the “adhesion to SBR” or“adhesion T-peel” test is based on ASTM D413. This test is used todetermine the adhesive bond strength between two rubber compounds, thesame or different, after curing. Generally, the compounds used to makeup the rubber (elastomeric) compositions are prepared on a three-rollmill to a thickness of 2.5 mm. An adhesive backing fabric is placed onthe back of each compound. Typically, approximately 500 grams of stockblended elastomeric composition yields 16 samples which is enough for 8adhesion tests in duplicate, wherein the calender is set to 2.5 mmguides spaced 11 cm apart.

The face of the two compounds are pressed and bonded to one another. Asmall Mylar tab is placed between the two layers of rubber compositions(SBR and test composition) on one end to prevent adhesion, and to allowapproximately 2.5 inches (6.35 cm) of tab area. The samples are thencure bonded in a curing press at the specified conditions. Die out 1inch (2.54 cm) ×6 inch (15.24 cm) specimen from each molded vulcanizedpiece. The tab of each specimen is held by a powered driven tensioningmachine (Instron 4104, 4202, or 1101) and pulled at 180° untilseparation between the two rubber compositions occurs. Force to obtainseparation and observations are then reported.

Other test methods are summarized in Table 1.

EXAMPLES

The present invention, while not meant to be limiting by, may be betterunderstood by reference to the following examples and Tables. Thefollowing symbols are used throughout this description to describerubber components of the invention: IBIMS {terpolymer;poly(isobutylene-co-p-methylstyrene-co-isoprene)}; BrIBIMS {(brominatedterpolymer; brominatedpoly(isobutylene-co-p-methylstyrene-co-isoprene)}; IBMS{poly(isobutylene-co-p-methylstyrene)}; BrIBMS{poly(isobutylene-co-p-methylstyrene-co-p-bromomethylstyrene)}; SBB{brominated star branched butyl rubber (poly(isobutylene-co-isoprene))};BR {polybutadiene}; NR {natural rubber}; SBR {styrene-butadiene rubber};and BIIR {brominated poly(isobutylene-co-isoprene)}.

The synthesis of the terpolymer useful in the invention was carried outin a set of 6 sample batch runs. Tertiary-butylchloride (t-BuCl) was theinitiator used in runs A-F, data for which is shown in Table 3A.

For the runs A-F, the batch experiments were 250 mL reactions inchloromethane at an initial temperature of −93° C. The initiator used inthe examples was t-butylchloride (Aldrich Chemical Co.) and the Lewisacid catalyst used was 25 wt % solution of EADC(ethylaluminumdichloride) in heptane. The t-butylchloride initiator andEADC catalyst were pre-mixed at 3/1 molar ratio in chloromethane anddiluted to a final total concentration of about 1 wt % solution inchloromethane.

The isobutylene used in the examples was dried by passing theisobutylene vapor through drying columns, and then condensed in a cleanflask in a dry box prior to use. The p-methylstyrene and isoprenemonomers used in the examples were distilled under vacuum to removemoisture and free radical inhibitor prior to use. The monomer feed blendused in the terpolymer synthesis of runs A-F was a 10 wt % totalmonomers in chloromethane with 80/10/10 wt % ratio ofisobutylene/isoprene/p-methylstyrene.

The terpolymerization experiments were carried out in 500 ml glassreactors in a standard nitrogen atmosphere enclosure box (dry box)equipped with a cooling bath for low temperature reactions. Eachpolymerization batch used 250 ml of the monomer feed blend contained80/10/10 wt % ratio of isobutylene/isoprene/p-methylstyrene at 10 wt %total monomers in chloromethane. After the monomer solution was cooleddown to desired reaction temperature (<−90° C.), the pre-chilledinitiator/catalyst mixture solution was added slowly to the reactor toinitiate the polymerization. The rate of catalyst solution addition wascontrolled to avoid excessive temperature buildup in the reactor. Thus,catalyst was added incrementally to the bulk-phase within the reactor.The amount of total catalyst solution added was adjusted based on, amongother factors, the accumulated temperature increases that correlate withamount of monomers consumed in the reactor. When desirable monomerconversion was reached (e.g., at least 50% conversion), a small amountof methanol was added to the reactor to quench the polymerizationreactions. The terpolymer was then isolated and dried in a vacuum ovenfor analysis.

The molecular weight and molecular weight distribution (Mw/Mn) of theresultant terpolymers were analyzed by standard Gel PermeationChromatography (GPC) techniques known in the art (described above). TheGPC analysis results of the terpolymers are shown in Table 3. The mole %ratios of monomer derived units in the final terpolymers obtained bystandard proton NMR technique are also shown in Table 3A. The compositeamount of unsaturated groups (also corresponding to the level ofisoprene {IP}) in the terpolymer of runs A-F is 4.14 mole %. Thecomposite amount of PMS in the final terpolymer of runs A-F is 4.64 mole%.

Bromination of the A-F terpolymer composite was carried out in standardround bottomed flasks using 5 wt % terpolymer solution in cyclohexane.In order to minimize free radical bromination, the reactor wascompletely shielded from light and a small amount (about 200 ppm basedon polymer charge) of BHT free radical inhibitor was added in thepolymer solution. A 10 wt % bromine solution in cyclohexane was preparedand transferred into a graduated addition funnel attached to thereactor. Desired amount of the bromine solution was then added dropwiseinto the terpolymer solution with vigorous agitation. The brominationreaction was quenched with excessive caustic solution 2-5 minutes afterthe bromine addition was completed. The excess caustic in theneutralized terpolymer solution was then washed with fresh water inseparatory funnel several times. The brominated terpolymer was isolatedby solvent precipitation in methanol and then dried in vacuum oven atmoderate temperature overnight.

Bromination resulted mostly in bromination of the unsaturation in thebackbone of the terpolymer, with some bromination of the PMS. The levelof bromine in the composite sample on the backbone is 0.80 mole %, and0.06 mole % on the PMS as determined by NMR (total 0.86 mole % bromine).This sample was used in example 3. Another batch of terpolymer wassubjected to bromination similarly to that above, resulting in acomposite bromine level of 1.1 mole % (±10%). This sample was used forexample 7.

In demonstrating the cure characteristics of the IBIMS, the A-Fcomposite, and other comparative compounds, examples 1-3 were mixed intwo stages using a Haake Rheomix™ 600 internal mixer. Elastomers,fillers, and processing oil were mixed in the first step. Ingredientsare listed in Table 3. The second step consisted of mixing the firststep masterbatch and adding all other chemical ingredients. Mixingcontinued for three minutes or until a temperature of 110° C. wasreached. An open two-roll mill was used to sheet out the stocks aftereach Haake mixing step.

Examples of the compositions (1-7) used to study the curecharacteristics of the terpolymer are found in Table 4, the propertiesof which are summarized in Table 5. Samples 1-7 represent the terpolymerin comparison with other known rubbers. Each sample 1-7 includes 60 phrN666 carbon black; 4 phr SP-1068 resin; 7 phr STRUKTOL 40 MS; 1 phrstearic acid; 8 phr CALSOL 810 processing oil; 0.15 phr MAGLITE-K; 1 phrKADOX 911 zinc oxide; 0.5 phr sulfur; and 1.25 phr MBTS. The cureproperties are summarized in Table 5, and the physical characteristicsare summarized in Table 6. Aged properties of samples 4-7, and adhesionto SBR tests, are summarized in Table 7. Finally, the dynamic properties(tangent delta) values of examples 4-7 are summarized in Table 8 andFIG. 1.

The results of the physical studies outlined in Tables 5-7 show that theBrIBIMS Compound 7 has similar cure properties to the otherisobutylene-based polymers studied: bromobutyl rubber, star-branchedbromobutyl rubber and BIMS. Slightly lower mechanical properties (100%and 300% modulus, tensile and energy to break values) are obtainedprimarily thought due to the lower molecular weight of the BrIBIMSterpolymer (see Table 6) as indicated by the much lower Mooney viscosityvalue obtained for the innerliner compound. The BrIBIMS innerlinerCompound 7 has the same desirably low air permeability as the otherisobutylene elastomers. However, surprisingly in spite of this lowmolecular weight the BrIBIMS Compound 7 has higher abrasion resistancevalues than the bromobutyl rubber (5) or star-branched bromobutyl rubber(4) innerliners and is comparable to the BIMS Compound 6. In addition,the BrIBIMS Compound 7 has higher adhesion to a SBR carcass compound anda higher tear strength than does the BIMS Compound 6.

Dynamic property testing shows that the BrIBIMS terpolymer Compound 7has higher tangent delta values at temperatures between +30° C. and −20°C. indicating potential improved dry, wet and winter tractionproperties, see FIG. 1. This property is useful in rubber products wheretraction or grip is an important performance property such as in tiretreads, shoe outsoles, and power transmission belts. Table 8 is asummary of the results shown in FIG. 1.

The examples 3 and 7 above were performed using a BrIBIMS terpolymerhaving a collective (combination of several batches) number averagemolecular weight of about 90,000. Given this relatively low molecularweight, it is surprising that the adhesion to SBR value in Table 7 is ashigh as 70 N/mm. Thus, while the tensile strength and energy to breakvalues of the example 7 BrIBIMS are low relative to, for example BIIR,this would be expected for a polymer having the relatively low numberaverage molecular weight exhibited in the example 7 BrIBIMS. In aprospective example BrIBIMS, the number average molecular weight of theterpolymer is between 300,000 and 800,000, or between 300,000 and600,000 in another embodiment. This terpolymer may be achieved byadjusting the reaction conditions such as the identity and/or quantityof initiator, the reactor temperature, and other factors. This 300,000to 800,000 number average molecular weight BrIBIMS terpolymer would beexpected to exhibit a further improved adhesion to SBR value of from 80to 300 N/mm or greater. The DIN Abrasion Index of this higher MWterpolymer would be greater than 60 in one embodiment, and greater than70 in yet another embodiment, and greater than 80 in yet anotherembodiment. Finally, the Mooney viscosity (ML (1+4) at 100° C.) of the300,000 to 800,000 number average molecular weight BrIBIMS terpolymerwould be from 50 to 70 units.

Thus, in a desirable embodiment, the terpolymer of the invention, with afiller and alternatively with other additional rubbers and othercomponents, exhibits an adhesion to SBR value at 100° C. of from greaterthan 70 N/mm in one embodiment, greater than 80 N/mm in anotherembodiment, greater than 100 N/mm in yet another embodiment, and greaterthan 200 N/mm in yet another embodiment, and from 70 to 400 N/mm in oneembodiment, and from 80 to 300 N/mm in yet another embodiment.

The terpolymer of the present invention, in combination with a suitablefiller, and alternatively, one or more additional secondary rubbers, canbe cured by any suitable means to form various useful articles. Inparticular, the cured terpolymers of the invention are suitable forautomotive tire components such as treads, sidewalls and, particularlysuitable for tire innerliners, innertubes, and other applications whereair barrier qualities are desirable. The terpolymer, or compositions ofthe terpolymer, may also be suitable for such articles as belts andhoses, vibrational damping devices, pharmaceutical stoppers andplungers, shoe soles and other shoe components, and other devices whereair impermeability and flexibility are important.

The composition of the present invention may be used in producinginnerliners for motor vehicle tires such as truck tires, bus tires,passenger automobile tires, motorcycle tires, off the road tires, andthe like. The oxygen permeability (MOCON) of the cured compositions ofthe invention is less than 10×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in oneembodiment, less than 9.5×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in anotherembodiment, and less than 9.0×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in yetanother embodiment, and less than 8.5×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C.in yet another embodiment; and the oxygen permeability may range from0.1×10⁻⁸ to 10×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in one embodiment, andfrom 1×10⁻⁸ to 9×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. in anotherembodiment, and from 1.5×10⁻⁸ to 9 ×10⁻⁸ cm³·cm/cm²·sec·atm at 65° C. inyet another embodiment.

The cured composition of the present invention, in combination with asuitable filler, and alternately, an additional rubber and othercomponents, may have a DIN Abrasion Index of from greater than 45 in oneembodiment, and greater than 50 in another embodiment, and greater than52 in yet another embodiment; and a DIN Abrasion Index from 30 to 80 inyet another embodiment, and from 40 to 70 in yet another embodiment, andfrom 45 to 65 in yet another embodiment.

Also, the cured composition of the present invention, in combinationwith a suitable filler, and alternately, an additional rubber and othercomponents, may have a Tangent Delta (G″/G′) value at −30° C. of greaterthan 0.60 in one embodiment, and greater than 0.70 in anotherembodiment, and greater than 0.80 in yet another embodiment, and from0.50 to 1.2 in yet another embodiment, from 0.60 to 1.1 in yet anotherembodiment, and from 0.70 to 1.1 in yet another embodiment. The TangentDelta (G″/G′) value at 0° C. of the cured composition may be greaterthan 0.20 in one embodiment, and greater than 0.25 in anotherembodiment, and greater than 0.30 in yet another embodiment, and from0.20 to 0.80 in yet another embodiment, from 0.25 to 0.70 in yet anotherembodiment, and from 0.25 to 0.65 in yet another embodiment.Compositions of the terpolymer would be expected, based on the tangentdelta values at 60° C., to have a similar heat buildup relative to theother components of, for example, a tire. Thus, there would be nohysteresis expected in using the terpolymer of the present invention ininnerliners and innertubes.

The present invention includes the use of the terpolymer described andcharacterized above in various compositions, and the method of makingthe terpolymer and compositions. One embodiment of the present inventionis an elastomeric composition suitable for an air barrier comprising afiller; a sulfur cure system; and at least one halogenated terpolymer ofC₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derived units,and p-alkylstyrene derived units.

Alternatively, the present invention can be described as a curedelastomeric composition comprising at least one halogenated terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units, wherein the composition iscured in the presence of a sulfur cure system; and wherein the adhesionto SBR value at 100° C. of the cured composition is from greater than 70N/mm.

The elastomeric composition may include at least one metal oxide,elemental sulfur, and optionally at least one accelerator in oneembodiment.

The filler of the elastomeric composition may be selected from carbonblack, silica, alumina, calcium carbonate, clay, mica, talc, titaniumdioxide, starch, wood flower, and mixtures thereof in anotherembodiment.

The elastomeric composition may also include a secondary rubber inanother embodiment, wherein the secondary rubber is selected fromnatural rubber, polybutadiene rubber, nitrile rubber, silicon rubber,polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched polyisobutylene rubber, star-branchedbrominated butyl rubber, poly(isobutylene-co-isoprene) rubber;halogenated poly(isobutylene-co-p-methylstyrene) and mixtures thereof.

In another embodiment of the elastomeric composition of the invention,the C₄ to C₈ isoolefin monomer is isobutylene; and the C₄ to C₁₄multiolefin monomer is isoprene in another embodiment; and thep-alkylstyrene is p-methylstyrene in yet another embodiment.

In yet another embodiment of the elastomeric composition, the terpolymeris brominated.

The bromine level of the terpolymer of the elastomeric composition maybe in the range of from 0.1 mole % to 2.5 mole % based on the totalmoles of monomer derived units in the terpolymer in one embodiment, andfrom 0.2 mole % to 2 mole % based on the total moles of monomer derivedunits in the terpolymer.

In yet another embodiment of the elastomeric composition, the terpolymerhas a number average molecular weight of from 300,000 to 800,000. In yetanother embodiment, the filler is carbon black, or blend of carbon blackand silica or an exfoliated clay in another embodiment.

The composition has certain desirable properties that make it suitablefor such articles as tire and shoe components, particularly in airbarriers. In one embodiment, the adhesion to SBR value at 100° C. isgreater than 100 N/mm, and greater than 200 N/mm in another embodiment.

The elastomeric composition has a DIN Abrasion Index of greater than 45units in one embodiment, and a tangent delta value of from greater than0.60 at −30° C. in another embodiment and a tangent delta value of fromgreater than 0.20 at 0° C. in yet another embodiment. The elastomericcomposition is thus suitable for such articles as tire innerliners andtreads, sidewalls, etc.

The present invention also includes an improved method of making aBrIBIMS terpolymer and compositions of the terpolymer. A method ofproducing an elastomeric terpolymer composition includes combining, in adiluent, C₄ to C₈ isoolefin monomers, C₄ to C₁₄ multiolefin monomers,and p-alkylstyrene monomers in the presence of a Lewis acid and at leastone initiator to produce the terpolymer.

In one embodiment of the method of making the terpolymer, the initiatoris described by the following formula:

wherein X is a halogen; R₁ is selected from hydrogen, C₁ to C₈ alkyls,and C₂ to C₈ alkenyls, aryl, and substituted aryl; R₃ is selected fromC₁ to C₈ alkyls, C₂ to C₈ alkenyls, aryls, and substituted aryls; and R₂is selected from C₄ to C₂₀₀ alkyls in one embodiment, and from C₄ to C₅₀alkyls in another embodiment, C₂ to C₈ alkenyls, aryls, and substitutedaryls, C₃ to C₁₀ cycloalkyls, and

wherein X is a halogen; R₅ is selected from C₁ to C₈ alkyls, and C₂ toC₈ alkenyls; R₆ is selected from C₁ to C₈ alkyls, C₂ to C₈ alkenylsaryls, and substituted aryls; and R₄ is selected from phenylene,biphenyl, α,ω-diphenylalkane and —(CH₂)_(n)—, wherein n is an integerfrom 1 to 10; and wherein R₁, R₂, and R₃ can also form adamantyl orbornyl ring systems.

In another embodiment of the method of making the terpolymer, the Lewisacid is selected from of aryl aluminum halides, alkyl-substituted arylaluminum halides, alkyl aluminum halides and a mixture thereof.

The Lewis acid is selected from the group of dialkyl aluminum halide,monoalkyl aluminum dihalide, aluminum tri-halide, ethylaluminumsesquichloride, and a mixture thereof in one embodiment, and is selectedfrom AlCl₃, EtAlCl₂, Et_(1.5)AlCl_(1.5), Et₂AlCl, and mixtures thereofin another embodiment.

In yet another embodiment of the method of making the terpolymer andcomposition, the dielectric constant of the diluent is greater than 6 at20° C., and greater than 9 at 20° C. in another embodiment. In anotherembodiment, the diluent is selected from methylcyclohexane, cyclohexane,toluene, carbon disulfide, ethyl chloride, methylchloride, methylenechloride, CHCl₃, CCl₄, n-butyl chloride, chlorobenzene, and mixturesthereof.

The method further includes the step of halogenating the terpolymer inanother embodiment.

In another embodiment of the method of making the terpolymer, thetemperature for the polymerization is between −10° C. and the freezingpoint of the polymerization system.

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to many differentvariations not illustrated herein. For these reasons, then, referenceshould be made solely to the appended claims for purposes of determiningthe true scope of the present invention.

All priority documents are herein fully incorporated by reference forall jurisdictions in which such incorporation is permitted. Further, alldocuments cited herein, including testing procedures, are herein fullyincorporated by reference for all jurisdictions in which suchincorporation is permitted.

TABLE 1 Test Methods Parameter Units Test Mooney Viscosity (BIMSpolymer) ML 1 + 8, 125° C., MU ASTM D 1646 (modified) Mooney Viscosity(composition) ML 1 + 4, 100° C., MU ASTM D 1646 Brittleness ° C. ASTM D746 Mooney Scorch Time T_(s)5, 125° C., minutes ASTM D 1646 Moving DieRheometer (MDR) @ 160° C., ±0.5° arc ML dNewton · m MH dNewton · mT_(s)2 minute T_(c)90 minute Cure rate dN · m/minute ASTM D 2084Physical Properties press cured Tc 90 + 2 min @ 160° C. Hardness Shore AASTM D 2240 Modulus MPa ASTM D 412-68 Tensile Strength MPa Elongation atBreak % Rebound % Zwick 5901.01 Rebound Tester ASTM D1054 or ISO 4662 orDIN 53512 Dispersion D scale — DisperGrader 1000 (Optigrade, Sweden)Abrasion Resistance (ARI) — ISO 4649 or DIN 53516 Energy N/mm Area underthe Elongation at break curve. Tangent Delta — Rheometrics ARES

TABLE 2 Components and Commercial Sources Component Brief DescriptionCommercial Source Budene ™ 1207 polybutadiene Goodyear (Akron, OH) BIIR2222 brominated ExxonMobil Chemical poly(isobutylene-co- Company(Houston, TX) isoprene), Mooney viscosity of 40–60 MU (1 + 8, 125° C.),2 wt % bromine CALSOL 810 processing oil; naphthenic R. E. Carroll(Trenton, NJ) oil EADC ethyl aluminum dichloride AKZO Nobel ChemicalEXXPRO ™ 89-4 5 wt % PMS, 0.75 mol % ExxonMobil Chemical BrPMS, Mooneyviscosity Company (Houston, TX) of 45 ± 5 MU (1 + 8, 125° C.)Isobutylene monomer ExxonMobil Chemical Company (Houston, TX) Isoprenemonomer Aldrich Chemical Company MAGLITE-K cure agent, magnesium C. P.Hall (Chicago, IL) oxide MBTS 2,2′-benzothiazyl disulfide SovereignChemical Co. (Akron, OH) p-methylstyrene (PMS) monomer Aldrich ChemicalCompany SP-1068 brominated phenol- Schenectady Internationalformaldehyde resin (Schenectady, NY) SBB 6222 star-branched butylrubber; ExxonMobil Chemical 2 wt % Br Company (Houston, TX) STRUKTOL40MS mixture of aliphatic, Struktol (Stow, OH) aromatic and naphthenicresins Stearic acid cure agent e.g., C. K. Witco Corp. (Taft, LA) Sulfurcure agent e.g., R. E. Carroll (Trenton, NJ) zinc oxide, KADOX ™ 911cure agent, zinc oxide Zinc Corp. of America (Monaca, PA)

TABLE 3 Reaction conditions and results for runs A–F to produceterpolymer using t-butylchloride as the initiator. Composite Condition AB C D E F (A–F) Moles monomer 0.390 0.390 0.390 0.390 0.390 0.390 —Volume Catalyst 48.0 66.0 75.5 50.0 51.5 65.5 — solution added (mL)†Change in 9.9 9.7 8.8 9.6 9.1 9.8 — temperature, ° C. Reaction time(min) 20.8 20.8 20.5 18.0 15.0 17.5 — % conversion 64.72 68.40 69.2461.64 58.68 59.68 — Mn 91,600 82,800 75,100 94,100 93,400 82,300 — Mw250,500 239,000 241,800 246,500 241,700 247,100 — Mp — 162,200 145,700168,900 175,900 158,900 — Mw/Mn 2.73 2.89 3.22 2.62 2.59 3.00 — Mole %unsaturated — — — — — — 4.14 groups (IP), H¹ NMR Mole % PMS in — — — — —— 4.64 interpolymer, H¹ NMR †Catalyst solution was 1.0 wt % EADC andt-BuCl mixture in chloromethane, wherein the EADC/t-BuCl molar ratio was3:1.

TABLE 4 Components of examples¹ Component 3 (mol 7 (mol (phr) 1 2 % Br)4 5 6 % Br) SBB 6222 100 — — 100 — — — BIIR 2222 — — — — 100 — — IBMS —100 — — — 100 — (EXXPRO 89-4) BrIBIMS — — 100 (0.86) — — — 100 (1.1)¹Each of samples 1–3 also include the following: 60 phr N666 carbonblack; 4 phr SP-1068 resin; 7 phr STRUKTOL 40 MS; 1 phr stearic acid; 8phr CALSOL 810 processing oil; 0.15 phr MAGLITE-K; 1 phr KADOX 911 zincoxide; 0.5 phr sulfur; and 1.25 phr MBTS.

TABLE 5 Cure properties of examples property 1 2 3 4 5 6 7 MDR 160° C.,0.5° arc ML, dN · m 1.12 1.86 0.51 1.22 1.33 1.53 0.48 MH, dN · m 5.477.6 4.84 5.12 6.06 8.09 3.51 MH-ML, dN · m 4.35 5.74 4.33 3.9 4.73 6.563.03 Ts2, min 8.83 10.42 5.87 5.52 4.8 6.06 2.08 T50, min 9.37 13.466.87 5.41 5.41 7.71 1.55 T90, min 16.66 24.96 22.91 10.28 12.16 13.5310.11

TABLE 6 Physical properties of examples property 1 2 3 4 5 6 7 MooneyViscosity, ML — — — 51.70 53.70 62.50 33.20 (1 + 4, 100° C.) 20%Modulus, MPa 0.58 0.65 0.58 0.57 0.53 0.68 0.64 100% Modulus, MPa 1.321.92 1.26 1.17 1.13 1.87 1.14 300% Modulus, MPa 4.40 5.85 3.81 3.65 3.685.72 3.01 Tensile, MPa 8.86 9.34 7.59 8.24 8.73 9.37 5.65 Elongation atBreak, % 693 658 754 730 754 720 787 Energy to Break, J 9.43 10.64 9.5610.53 12.00 13.18 8.73 Shore A Hardness at 23° C. 48.3 51.9 49.1 48.547.5 51.7 44.7 MOCON oxygen 9.789 8.534 9.673 11.6 11.0 9.9 10.7permeability (65° C.) (10⁸, cm³ · cm/cm² · sec · atm) Dispersion D scale5.6 6.9 6.3 5 6.2 7.2 6.6

TABLE 7 Aged properties of examples 4–7, and adhesion to SBR carcassproperty 4 5 6 7 Rebound, % 10.2 10.2 9.9 8.8 Aging, 72 hrs @ 125° C.Aged 20% Modulus, 1.11 0.99 1.15 1.10 MPa Aged 100% Modulus, 2.46 2.533.50 2.75 MPa Aged 300% Modulus, 6.20 6.60 8.75 6.30 MPa Aged Tensile,MPa 7.15 8.11 10.42 6.88 Aged Elongation, % 391 525 467 380 Aged energyto break, J 5.13 9.45 10.42 5.35 Adhesion to SBR 118.8 245.4 39.4 70.2carcass @ 100° C., N/mm DIN Abrasion resistance 44 43 53 55 Index Tearresistance, N/mm 3.54 7.89 1.29 1.79

TABLE 8 Representative Tangent Delta values for the elastomers in FIG.1, examples 4–7 Tan Delta values at given temperatures, ° C. SBB (4)BIIR (5) BIMS (6) BrIBIMS (7) −30 0.849 0.915 1.007 0.980 0 0.369 0.4040.429 0.528 30 0.199 0.226 0.166 0.239 60 0.154 0.179 0.125 0.191

1. A cured elastomeric composition comprising a halogenated terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units, wherein the composition iscured in the presence of a sulfur cure system; and wherein the adhesionto SBR value at 100° C. of the cured composition is greater than 70N/mm.
 2. The cured elastomeric composition of claim 1, also comprising ametal oxide, fatty acid, and an accelerator.
 3. The cured elastomericcomposition of claim 1, also comprising a filler selected from carbonblack, modified carbon black, silica, alumina, calcium carbonate, clay,mica, talc, titanium dioxide, starch, wood flower, and mixtures thereof.4. The cured elastomeric composition of claim 1, also comprising asecondary rubber selected from natural rubber, polybutadiene rubber, andmixtures thereof.
 5. The cured elastomeric composition of claim 1, alsocomprising a secondary rubber selected from nitrile rubber, siliconrubber, polyisoprene rubber, poly(styrene-co-butadiene) rubber,poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber,ethylene-propylene rubber, brominated butyl rubber, chlorinated butylrubber, halogenated isoprene, halogenated isobutylene copolymers,polychloroprene, star-branched polyisobutylene rubber, star-branchedbrominated butyl rubber, poly(isobutylene-co-isoprene) rubber;halogenated poly(isobutylene-co-p-methylstyrene) and mixtures thereof.6. The cured elastomeric composition of claim 1, wherein the C₄ to C₈isoolefin is isobutylene.
 7. The cured elastomeric composition of claim1, wherein the C₄ to C₁₄ multiolefin is selected from cyclopentadieneand isoprene.
 8. The cured elastomeric composition of claim 1, whereinthe p-alkylstyrene is p-methylstyrene.
 9. The cured elastomericcomposition of claim 1, wherein the terpolymer is brominated.
 10. Thecured elastomeric composition of claim 9, wherein the bromine is presentin the terpolymer in the range of from 0.1 mole % to 2.5 mole % based onthe total moles of monomer derived units in the terpolymer.
 11. Thecured elastomeric composition of claim 9, wherein the bromine is presentin the terpolymer in the range of from 0.2 mole % to 2 mole % based onthe total moles of monomer derived units in the terpolymer.
 12. Thecured elastomeric composition of claim 1, wherein the terpolymer has anumber average molecular weight of from 300,000 to 800,000.
 13. Thecured elastomeric composition of claim 1, wherein the adhesion to SBRvalue at 100° C. is greater than 100 N/mm.
 14. The cured elastomericcomposition of claim 1, wherein the adhesion to SBR value at 100° C. isgreater than 200 N/mm.
 15. The cured elastomeric composition of claim 1,also comprising carbon black.
 16. The cured elastomeric composition ofclaim 15, having a DIN Abrasion Index of greater than 45 units.
 17. Thecured elastomeric composition of claim 15, having a tangent delta valueof greater than 0.60 at −30° C.
 18. The cured elastomeric composition ofclaim 15, having a tangent delta value of greater than 0.20 at 0° C. 19.The cured elastomeric composition of claim 1, also comprising a fillerpresent from 5 to 100 phr.
 20. The elastomeric composition of claim 1,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 21. An innerlinercomprising the cured composition of claim
 1. 22. An innertube comprisingthe cured composition of claim
 1. 23. An elastomeric compositioncomprising a filler; a sulfur cure system; and a halogenated terpolymerof C₄ to C₈ isoolefin derived units, C₄ to C₁₄ multiolefin derivedunits, and p-alkylstyrene derived units.
 24. The elastomeric compositionof claim 23, also comprising a metal oxide, fatty acid, and anaccelerator.
 25. The elastomeric composition of claim 23, wherein thefiller is selected from carbon black, modified carbon black, silica,alumina, calcium carbonate, clay, mica, talc, titanium dioxide, starch,wood flower, and mixtures thereof.
 26. The elastomeric composition ofclaim 23, also comprising a secondary rubber selected from naturalrubber, polybutadiene rubber, and mixtures thereof.
 27. The elastomericcomposition of claim 23, also comprising a secondary rubber selectedfrom nitrile rubber, silicon rubber, polyisoprene rubber,poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene) rubber,styrene-isoprene-butadiene rubber, ethylene-propylene rubber, brominatedbutyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 28. Theelastomeric composition of claim 23, wherein the C₄ to C₈ isoolefin isisobutylene.
 29. The elastomeric composition of claim 23, wherein the C₄to C₁₄ multiolefin is selected from cyclopentadiene and isoprene. 30.The elastomeric composition of claim 23, wherein the p-alkylstyrene isp-methylstyrene.
 31. The elastomeric composition of claim 23, whereinthe terpolymer is brominated.
 32. The elastomeric composition of claim31, wherein the bromine is present in the terpolymer in the range offrom 0.1 mole % to 2.5 mole % based on the total moles of monomerderived units in the terpolymer.
 33. The elastomeric composition ofclaim 31, wherein the bromine is present in the terpolymer in the rangeof from 0.2 mole % to 2 mole % based on the total moles of monomerderived units in the terpolymer.
 34. The elastomeric composition ofclaim 23, wherein the terpolymer has a number average molecular weightof from 300,000 to 800,000.
 35. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 70 N/mm.
 36. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 100 N/mm.
 37. The elastomeric composition of claim 23,wherein the adhesion to SBR value at 100° C. of the cured composition isgreater than 200 N/mm.
 38. The elastomeric composition of claim 23,wherein the filler is carbon black.
 39. The elastomeric composition ofclaim 23, wherein the cured composition has a DIN Abrasion Index ofgreater than 45 units.
 40. The elastomeric composition of claim 23,wherein the cured composition has a tangent delta value of greater than0.60 at −30° C.
 41. The elastomeric composition of claim 23, wherein thecured composition has a tangent delta value of greater than 0.20 at 0°C.
 42. The elastomeric composition of claim 23, wherein the filler ispresent from 5 to 100 phr.
 43. The elastomeric composition of claim 23,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 44. An innerlinercomprising the composition of claim
 23. 45. An innertube comprising thecomposition of claim
 23. 46. An air barrier comprising the compositionof claim
 23. 47. An elastomeric composition comprising a sulfur curesystem; a halogenated terpolymer of C₄ to C₈ isoolefin derived units, C₄to C₁₄ multiolefin derived units, and p-alkylstyrene derived units; anda secondary rubber.
 48. The elastomeric composition of claim 47, alsocomprising a metal oxide, fatty acid, and an accelerator.
 49. Theelastomeric composition of claim 47, also comprising a filler selectedfrom modified carbon black, carbon black, silica, alumina, calciumcarbonate, clay, mica, talc, titanium dioxide, starch, wood flower, andmixtures thereof.
 50. The elastomeric composition of claim 47, whereinthe filler is carbon black.
 51. The elastomeric composition of claim 47,wherein the secondary rubber is selected from natural rubber,polybutadiene rubber, nitrile rubber, silicon rubber, polyisoprenerubber, poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene)rubber, styrene-isoprene-butadiene rubber, ethylene-propylene rubber,brominated butyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 52. Theelastomeric composition of claim 47, wherein the secondary rubber ispresent from 5 to 50 phr.
 53. The elastomeric composition of claim 47,wherein the C₄ to C₈ isoolefin monomer is isobutylene.
 54. Theelastomeric composition of claim 47, wherein the C₄ to C₁₄ multiolefinmonomer is isoprene.
 55. The elastomeric composition of claim 47,wherein the p-alkylstyrene is p-methylstyrene.
 56. The elastomericcomposition of claim 47, wherein the terpolymer is brominated.
 57. Theelastomeric composition of claim 47, wherein the halogen is present inthe terpolymer in the range of from 0.1 mole % to 2.5 mole % based onthe total moles of monomer derived units in the terpolymer.
 58. Theelastomeric composition of claim 47, wherein the halogen is present inthe terpolymer in the range of from 0.2 mole % to 2 mole % based on thetotal moles of monomer derived units in the terpolymer.
 59. Theelastomeric composition of claim 47, wherein the terpolymer has a numberaverage molecular weight of from 80,000 to 1,000,000.
 60. Theelastomeric composition of claim 47, wherein the terpolymer has a numberaverage molecular weight of from 300,000 to 800,000.
 61. The elastomericcomposition of claim 47, wherein the adhesion to SBR value at 100° C. isgreater than 70 N/mm.
 62. The elastomeric composition of claim 47,wherein the adhesion to SBR value at 100° C. is greater than 100 N/mm.63. The elastomeric composition of claim 47, wherein the adhesion to SBRvalue at 100° C. is greater than 200 N/mm.
 64. The elastomericcomposition of claim 47, wherein the filler is carbon black and theterpolymer is brominated.
 65. The elastomeric composition of claim 47,having a DIN Abrasion Index of greater than 90 units.
 66. Theelastomeric composition of claim 47, having a tangent delta value offrom greater than 0.60 at −30° C.
 67. The elastomeric composition ofclaim 47, having a tangent delta value of from greater than 0.25 at 0°C.
 68. The elastomeric composition of claim 47, wherein the filler ispresent from 10 to 100 phr.
 69. The elastomeric composition of claim 47,wherein the filler is present from 40 to 80 phr.
 70. An innerlinercomprising the composition of claim
 47. 71. An air barrier comprisingthe composition of claim
 47. 72. An innertube comprising the compositionof claim
 47. 73. An air barrier comprising a filler; a sulfur curesystem; and a halogenated terpolymer of C₄ to C₈ isoolefin derivedunits, C₄ to C₁₄ multiolefin derived units, and p-alkylstyrene derivedunits; wherein the DIN Abrasion Index of the air barrier is greater than50 units.
 74. The air barrier of claim 73, also comprising a metaloxide, fatty acid, and an accelerator.
 75. The air barrier of claim 73,wherein the filler is selected from carbon black, modified carbon black,silica, alumina, calcium carbonate, clay, mica, talc, titanium dioxide,starch, wood flower, and mixtures thereof.
 76. The air barrier of claim73, also comprising a secondary rubber selected from natural rubber,polybutadiene rubber, nitrile rubber, silicon rubber, polyisoprenerubber, poly(styrene-co-butadiene) rubber, poly(isoprene-co-butadiene)rubber, styrene-isoprene-butadiene rubber, ethylene-propylene rubber,brominated butyl rubber, chlorinated butyl rubber, halogenated isoprene,halogenated isobutylene copolymers, polychloroprene, star-branchedpolyisobutylene rubber, star-branched brominated butyl rubber,poly(isobutylene-co-isoprene) rubber; halogenatedpoly(isobutylene-co-p-methylstyrene) and mixtures thereof.
 77. The airbarrier of claim 73, wherein the C₄ to C₈ isoolefin monomer isisobutylene.
 78. The air barrier of claim 73, wherein the C₄ to C₁₄multiolefin monomer is selected from cyclopentadiene and isoprene. 79.The air barrier of claim 73, wherein the p-alkylstyrene isp-methylstyrene.
 80. The air barrier of claim 73, wherein the terpolymeris brominated.
 81. The air barrier of claim 80, wherein the bromine ispresent in the terpolymer in the range of from 0.1 mole % to 2.5 mole %based on the total moles of monomer derived units in the terpolymer. 82.The air barrier of claim 80, wherein the bromine is present in theterpolymer in the range of from 0.2 mole % to 2 mole % based on thetotal moles of monomer derived units in the terpolymer.
 83. The airbarrier of claim 73, wherein the terpolymer has a number averagemolecular weight of from 80,000 to 1,000,000.
 84. The air barrier ofclaim 73, wherein the terpolymer has a number average molecular weightof from 300,000 to 800,000.
 85. The air barrier of claim 73, wherein theadhesion to SBR value at 100° C. is greater than 100 N/mm.
 86. The airbarrier of claim 73, wherein the adhesion to SBR value at 100° C. isgreater than 200 N/mm.
 87. The air barrier of claim 73, wherein thefiller is carbon black.
 88. The air barrier of claim 73, having a DINAbrasion Index of greater than 50 units.
 89. The air barrier of claim73, having a tangent delta value of from greater than 0.60 at −30° C.90. The air barrier of claim 73, having a tangent delta value of fromgreater than 0.20 at 0° C.
 91. The air barrier of claim 73, wherein thefiller is present from 5 to 100 phr.
 92. The air barrier of claim 73,wherein the multiolefin derived units are present in the terpolymer from0.2 wt % to 30 wt % and the p-alkylstyrene derived units are presentfrom 0.5 wt % to 30 wt % by weight of the terpolymer.
 93. An innerlinerfor an automotive tire comprising the air barrier of claim
 73. 94. Aninnertube comprising the air barrier of claim 73.